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WILLIAM'S HEMATOLOGY > 6 Hematology of the Fetus and the Newborn > Flashcards

6 Hematology of the Fetus and the Newborn Flashcards

1
Q

The appearance of primitive erythroid cells in blood islands of the yolk sac begin at ________ of gestation

A

Day 18 of gestation

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2
Q

Primitive erythroblasts have extremely large size, with an estimated mean cell volume (MCV) of greater than 400 fL/cell, yolk sac erythroblasts have been termed

A

Megaloblasts

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3
Q

In humans, primitive erythroblasts begin to enter the embryo proper at days ________of gestation with the onset of cardiac contractions and circulate until approximately _______weeks of gestation

A

days 21–22 of gestation

12 weeks of gestation

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4
Q

The initial wave of primitive hematopoietic progenitors is followed by a second wave of yolk sac–derived definitive erythroid progenitors, termed

A

Burst-forming units–erythroid (BFU-E)

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5
Q

BFU-E are present in the human yolk sac as early as ______ weeks’ gestation and are found in the fetal liver by ______ weeks’ gestation

A

yolk sac: 4 weeks gestation

fetal liver: 5 weeks gestation

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6
Q

Between 7 and 15 weeks of gestation, _______% of the liver cells are hematopoietic.

A

60%

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7
Q

The liver serves as the primary source of red cells from the ____________week of gestation

A

9th to the 24th week of gestation

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8
Q

Are smaller than yolk sac–derived primitive megaloblasts and contain one-third the amount of hemoglobin

A

Fetal liver–derived definitive “macrocytes”

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9
Q

TRUE OR FALSE

Fetal liver–derived erythroid progenitors can differentiate in vitro with erythropoietin alone, in contrast to adult marrow–derived BFU-E, which requires erythropoietin plus interleukin (IL)-3 or stem cell factor.

A

TRUE

Fetal liver–derived erythroid progenitors can differentiate in vitro with erythropoietin alone, in contrast to adult marrow–derived BFU-E, which requires erythropoietin plus interleukin (IL)-3 or stem cell factor.

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10
Q

Erythropoietin transcripts also are present in the developing human kidney as early as

A

17 weeks’ gestation

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11
Q

Megakaryocytes are present in the liver by __________weeks of gestation, and platelets are first evident in the circulation at ________ weeks of gestation

A

6 weeks of gestation

8–9 weeks of gestation

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12
Q

Granulopoiesis is present in the liver parenchyma as early as ______ weeks of gestation, and small numbers of circulating leukocytes are present at the ______ week of gestation.

A

7 weeks of gestation

11th week of gestation

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13
Q

G-CSF is expressed by hepatocytes at ______ weeks gestation.

A

14 weeks gestation

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14
Q

B-cell progenitors are present in the fetal liver by ___weeks of gestation, and circulating lymphocytes are present at ____weeks’ gestation.

A

7 weeks of gestation

9 weeks gestation

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15
Q

T lymphocytes are found only rarely before _______ weeks’ gestation

A

12 weeks’ gestation

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16
Q

Hematopoietic cells are first seen in the marrow of _______week embryos, and they remain confined to the ______________ until 15 weeks’ gestation

A

10- to 11-week

Diaphyseal regions of long bones

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17
Q

Myeloid cells predominate by ______ weeks’ gestation, and the myeloid-to-erythroid ratio approaches the adult level of 3:1 by______weeks’ gestation.

A

12 weeks’ gestation

21 weeks’ gestation.

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18
Q

TRUE OR FALSE

Macrophage cells in the fetal marrow, but not in the fetal liver, express the lipopolysaccharide receptor CD14.

A

TRUE

Macrophage cells in the fetal marrow, but not in the fetal liver, express the lipopolysaccharide receptor CD14.

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19
Q

A massive expansion of B-cell progenitors occurs in the fetal marrow between __________ weeks of gestation.

A

11 and 20 weeks of gestation

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20
Q

The marrow becomes the major site of hematopoiesis after the ________ week of gestation and remains so throughout the remainder of fetal life.

A

24th week of gestation

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21
Q

Chromosome location

α-globin gene cluster:
β-globin gene cluster:

A

α-globin gene cluster: Chromosome 16
β-globin gene cluster: Chromosome 11

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22
Q

The major hemoglobin in embryos younger than 5 weeks’ gestation

A

Hgb Gower-1 (ζ2ε2)

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23
Q

Found in embryos with a gestational age as young as 4 weeks and is absent in embryos older than 13 weeks.

A

Hgb Gower-2 (α2ε2)

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24
Q

Found in young embryos but persists in infants with homozygous α-thalassemia

A

Hgb Portland (ζ2γ2)

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25
Q

The major hemoglobin of fetal life

A

Hgb F (α2γ2)

26
Q

Synthesis of Hgb A can be demonstrated in fetuses as young as_____ weeks’ gestation.

A

9 weeks’ gestation

27
Q

The fetal hemoglobin concentration in blood decreases after birth by approximately ______ per week and is generally less than 2% to 3% of the total hemoglobin by 6 months of age.

A

3% per week

28
Q

Normal adult levels of Hgb A2 are achieved by________months of age.

A

4 months of age

29
Q

Increased proportions of Hgb F at birth have been reported in infants who are

A

Small for gestational age, who have experienced chronic intrauterine hypoxia, who have trisomy 13, or who have died from sudden infant death syndrome (SIDS)

30
Q

Decreased levels of Hgb F at birth are found in

A

trisomy 21

31
Q

Delay of cord clamping may increase the blood volume and red cell mass of the infant by as much as ______%.

A

55%

32
Q

TRUE OR FALSE

A venous hemoglobin concentration of less than 14 g/dL in a term infant or a fall in hemoglobin or hematocrit level in the first postnatal day is abnormal.

A

TRUE

A venous hemoglobin concentration of less than 14 g/dL in a term infant or a fall in hemoglobin or hematocrit level in the first postnatal day is abnormal.

33
Q

The red cells of newborns are macrocytic, with an MCV in excess of 110 fL

The MCV begins to fall after the first week, reaching adult values by the ______ week

A

Ninth week

34
Q

TRUE OR FALSE

In several, but not all,studies, premature infants at birth had lower hemoglobin levels, higher reticulocyte counts, and higher nucleated red cell counts than did the term infants.

A

TRUE

In several, but not all,studies, premature infants at birth had lower hemoglobin levels, higher reticulocyte counts, and higher nucleated red cell counts than did the term infants.

35
Q

Physiologic anemia of the newborn is more pronounced during

A

5–8 weeks

36
Q

The lowest hemoglobin values in the term infant occur at approximately

A

2 months of age

37
Q

Erythropoietin can be measured after the ______ postnatal day, corresponding to the recovery from physiologic anemia.

A

60th postnatal day

38
Q

Symptoms of hyperviscosity in infants

A

Irritability, hypotonia, tremors, or poor suck reflex

39
Q

TRUE OR FALSE

The i antigen is expressed strongly, whereas the I antigen and the A and B antigens are expressed only weakly on neonatal red cells.

A

TRUE

The i antigen is expressed strongly, whereas the I antigen and the A and B antigens are expressed only weakly on neonatal red cells.

40
Q

By 1 year of age, the i antigen is undetectable, and the ABH antigens increase to adult levels by age ____ years

A

3 years

41
Q

The average of several studies of mean half-life of newborn red cells is ______ days.

A

60–80 days

42
Q

The oxygen affinity of cord blood is (lesser or greater) than that of maternal blood, because the affinity of Hgb F for 2,3-bisphosphoglycerate (2,3-BPG) is less than that of Hgb A.

A

greater

Consequently, the red cell oxygen equilibrium curve of the newborn is shifted to the left of that of the adult

43
Q

TRUE OR FALSE

The absolute number of segmented neutrophils rises in both term and premature infants in the first 24 hours.

A

TRUE

The absolute number of segmented neutrophils rises in both term and premature infants in the first 24 hours.

44
Q

The predominant cells in the first few days after birth.

A

Segmented granulocytes

45
Q

Becomes the most numerous cell and remains so during the first 4 years of life.

A

Lymphocyte

46
Q

An absolute eosinophil count of greater than 0.7 × 109/L was found in 76% of premature infants at 2–3 weeks of age.

Eosinophilia is associated in the ff conditions:

A

Coincided with the establishment of steady weight gain
Use of total parenteral nutrition
Endotracheal intubation
Blood transfusions

47
Q

In term infants, opsonic activity is normal for Staphylococcus aureus, but it is low for _____ and ______________.

Diminished opsonic antibody is associated with ___________ infection and represents one risk factor for neonatal infection.

A

yeast and Escherichia coli

group B streptococcal infection

48
Q

In premature infants, opsonic activity is low for________ and ___________ but is normal for Pseudomonas aeruginosa.

A

S. aureus and Serratia marcescens

49
Q

TRUE OR FALSE

Chemotactic function of leukocytes is low in neonates, whereas random motility is normal.

A

TRUE

Chemotactic function of leukocytes is low in neonates, whereas random motility is normal.

50
Q

TRUE OR FALSE

Phagocytosis of bacteria and latex granules by neutrophils from premature and term infants is normal.

A

TRUE

Phagocytosis of bacteria and latex granules by neutrophils from premature and term infants is normal.

51
Q

Ig___ levels of term infants are similar to maternal levels because of transplacental transfer

A

IgG

52
Q

Breastfeeding provides some transfer of antibodies, particularly _____________

A

Secretory IgA, lysozyme, and lactoferrin

53
Q

INCREASE OR DECREASE

Factors II, IX, X, XI, XII; prekallikrein; and high-molecular-weight kininogen

Factor VIII

Von Willebrand factor

A

Factors II, IX, X, XI, XII; prekallikrein; and high-molecular-weight kininogen: DECREASE

Factor VIII : SAME

Von Willebrand factor: INCREASE

54
Q

These factors decrease during the first 3–4 days after birth

A

Factors II (prothrombin), VII, IX, and X

**require vitamin K

55
Q

A hemorrhagic diathesis also may occur later, 2–12 weeks after birth, as a result of lack of vitamin K

A

Late hemorrhagic disease of the newborn or acquired prothrombin complex deficiency

56
Q

Frequently is the presenting event in Late hemorrhagic disease of the newborn

A

Intracranial hemorrhage

57
Q

The current recommendation of the American Academy of Pediatrics for Vitamin K

A

Vitamin K1, 0.5–1.0 mg, be administered intramuscularly at birth

58
Q

Arterial and venous thromboses are relatively frequent in newborns compared with other age groups, but greater than 90% of arterial and greater than 80% of venous clots are related to ___________

A

Catheters

59
Q

Drug that cause: Decreased
hemoglobin

A

Antiretroviral agents in combination

60
Q

Drug that cause: bleeding

A

Aspirin: Interference with platelet function

Diazoxide: Thrombocytopenia

Phenytoin (Dilantin/phenobarbital): Depletion of vitamin K–dependent coagulation factors by hepatic enzyme induction and factor degradation

Rifampin/isoniazid: Depletion of vitamin K–dependent coagulation factors

Thiazides: Thrombocytopenia

Warfarin (Coumadin): Known depletion of vitamin K–dependent coagulation factors by blocking carboxylation

61
Q

Drug that cause: kernicterus

A

Aspirin: Displacement of bilirubin from albumin

Sulfonamides: Displacement of bilirubin from albumin

WILLIAM'S HEMATOLOGY (89 decks)

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